Great enhancement of polarization in the (Ba0.67Sr0.33TiO3/LaNiO3)n multilayer thin films

Abstract

The periodic (Ba0.67Sr0.33TiO3/LaNiO3)n multilayer thin films were prepared on Pt (111)/SiO2/Si (100) substrates by radio-frequency magnetron sputtering technology. It is found that the electric polarization of the thin films can be enhanced by the periodic hetero-structures strongly. For the five periods multilayer thin films, the frequency dependence of the apparent dielectric constant show almost constant high values of dielectric constant (>2100) and relatively low loss tangent (<0.1) below 10 kHz. The remanent polarization (Pr) and the max polarization (Pmax) obtained from the P–E hysteresis loops, are 15.4 μC/cm2 and 66.2 μC/cm2, respectively. The temperature dependencies of the pyroelectric coefficients were measured by a dynamic technique. The intrinsic pyroelectric coefficient and material merit figure of the periodic BST/LNO multilayer films are 4.93425 × 10−8 C cm−2 K−1 and 0.39 × 10−5 Pa−1/2.